Human health will suffer when climate change strips back the nutritional content of crops, according to new research, which has stated that South East Asia will bear the brunt of the burden.

In a special collection of papers, researchers have weighed-up the impact climate change will have on disease risk, iron and zinc deficiency, and the availability of rice, wheat, potatoes and other staple crops.Their estimates predict a huge disease burden they say will disproportionately affect South-East Asian and sub-Saharan African countries.

This week, sees the first papers in PLOS Medicine​’s Special Issue on Climate Change and Health being published.

In a research article, Christopher Weyant of Stanford University and colleagues predict reduced crop nutritional content and subsequent health disparities due to increased carbon dioxide levels associated with climate change.

In their country-level modelling study, the authors incorporate estimates of climate change, crop nutrient concentrations, dietary patterns and disease risk into a model of iron and zinc deficiency.

Their estimates predict a disease burden of approximately 125.8 million disability-adjusted life-years (DALYs) globally over the period from 2015 to 2050, disproportionately affecting South-East Asian and sub-Saharan African countries.

"We estimated that zinc and iron deficiencies would induce 1,072.9 million disability-adjusted life years (DALYs) globally over the period 2015 to 2050,"​ wrote the researchers.

Exisiting problems

"In the presence of increasing carbon dioxide concentrations, we estimated that decreasing zinc and iron concentrations of crops would induce an additional 125.8 million DALYs globally over the same period. This carbon-dioxide-induced disease burden is projected to disproportionately affect nations in the World Health Organization’s South-East Asia and African Regions (44.0 and 28.5 million DALYs, respectively), which already have high existing disease burdens from zinc and iron deficiencies." ​

In another article, Kristie Ebi of the University of Washington, USA and Lewis Ziska of the Department of Agriculture-ARS, Adaptive Cropping Systems Laboratory, Mississippi, USA continue the theme of crop nutrition in a changing climate.

They reveal and how rising carbon dioxide concentrations and climate change are expected to decrease the quality, quantity, and availability of rice, wheat, potatoes and other staple crops.

They outline major knowledge gaps and investments needed to protect population health, particularly among the most vulnerable.

"Increasing average temperatures and changing precipitation patterns are already reducing crop and food production in several world regions," ​they write.

"Local temperature increases in excess of about 1˚C above pre-industrial levels are projected to have further negative effects on yields for major crops (wheat and rice) in tropical and temperate regions. ​

"Furthermore, the negative effects of extreme weather and climate events, such as increases in the frequency, intensity, and duration of heatwaves, on production can result in rapid food and cereal price increases, reducing access to food, particularly among the poor. Together, increasing emissions of CO2 could decrease the quality, quantity, and availability of cereal crops important for the health of humans and, potentially, the animals that are important sources of protein.​

The Special Issue​ will feature further publications over the coming weeks.